Issued at 300 PM CST Tue Oct 01 2024
000 WTPZ41 KNHC 012055 TCDEP1 Tropical Depression Eleven-E Discussion Number 1 NWS National Hurricane Center Miami FL EP112024 300 PM CST Tue Oct 01 2024 The small area of low pressure we have been monitoring for the past couple of days has become well-defined on satellite imagery this afternoon and was confirmed with recent scatterometer data. There has been enough organized deep convection today to consider this a tropical depression, as suggested by the Data-T estimate from TAFB, and the initial wind speed is set to 30 kt in accordance with the max believable scatterometer values. The initial motion is an uncertain 360/4 kt. The depression has been moving northward on the eastern end of the monsoon trough, and this general track is anticipated through landfall with little change seen in the steering flow for the next day or two. However, the model guidance is all over the place, owing to differences in the initial depth of the tropical depression and strength of the circulation associated with the monsoon trough and Invest 97E. The ECMWF model seems to have the best representation of the initial vortex, and the track forecast heavily leans on that model solution, especially given its recent successes with cyclones in that area. However, there is considerable spread in the guidance, and the tropical storm warning is larger than typical based on that uncertainty. Northeasterly shear is expected to continue to affect the depression through landfall, though very warm SSTs and a moist mid-level environment should promote some strengthening. These conditions would seem to favor intensification through landfall, and the first forecast shows a mid-range tropical storm, above most of the model guidance. At this point, extreme rainfall and flash flooding seem to be the biggest threats from this system. KEY MESSAGES: 1. The depression is forecast to become a tropical storm later tonight or on Wednesday. A Tropical Storm Warning is in effect for a portion of the coastline of southern Mexico, where tropical storm conditions are expected to begin on Wednesday. 2. Tropical Depression Eleven-E will likely bring heavy rainfall to portions of southern Mexico and Guatemala this week. Flooding and mudslides, especially in areas of steep terrain, are possible, especially from western Guatemala into portions of the Mexican states of Chiapas, Oaxaca, Veracruz, and Tabasco. FORECAST POSITIONS AND MAX WINDS INIT 01/2100Z 15.1N 94.6W 30 KT 35 MPH 12H 02/0600Z 15.5N 94.6W 35 KT 40 MPH 24H 02/1800Z 15.9N 94.6W 45 KT 50 MPH 36H 03/0600Z 16.5N 94.6W 45 KT 50 MPH...INLAND 48H 03/1800Z 17.1N 94.6W 20 KT 25 MPH...POST-TROP/INLAND 60H 04/0600Z...DISSIPATED $$ Forecaster Blake